The present invention relates to a connection device for cabinets of electrical panels and to a cabinet which uses said device; more particularly, the connection device according to the invention allows to connect the structure elements of a cabinet for an electrical panel with a solution which stands out owing to its simplicity both in terms of production and in terms of practical use, allowing to facilitate assembly and reduce the costs entailed by its provision. Generally, cabinets for low-voltage electrical panels are specifically designed and built so as to meet the functional and installation requirements of the components that constitute the panel. It is in fact known that electrical panels use a system of mutually parallel metallic bars, each of which is connected to a corresponding polarity of a power supply system. Inside the cabinet, the bars are electrically connected to the devices used in the panel, for example circuit breakers, and are geometrically coupled to appropriate insulation and support devices; said insulation and support devices, in addition to mutually electrically insulating the bars, allow to connect them to the structure of the cabinet. In this manner, any electrodynamic stresses produced by the flow of current in the bars are discharged onto the structure of the cabinet, which accordingly must have adequate structural strength characteristics. Furthermore, the electrical devices are arranged on one or more fixing guides, which are connected to the frame of the cabinet either directly or by using additional connecting elements. In order to meet these requirements, cabinets are generally provided with a structure shaped like a parallelepiped, inside which there is an adequate space suitable to accommodate the components of the panel and whose frame allows the anchoring of the elements that support said components, of the cladding panels and of the door of the cabinet.
In particular, the frame comprises two subframes which respectively constitute the lower and upper bases of the parallelepipedal structure; said subframes are typically constituted by four angular elements, generally known as three-way corner joints, which are mutually connected in pairs by virtue of profiled elements arranged substantially in a horizontal position and commonly known as cross-members. In turn, the subframes are mutually connected by using vertical profiled elements, or uprights, each of which connects two corresponding joints. Holes are furthermore provided along the vertical extension of the uprights for the direct fixing of the supporting elements of the electrical devices and of the distribution bars, or for the fixing of intermediate cross-members to which said supporting elements are connected.
In the current state of the art, the methods by which the various profiled elements of the frame are mutually connected are not fully satisfactory. The connection between the pairs of elements, for example a corner joint and a cross-member or an upright and a joint, in fact occurs by using a plurality of fixing screws, at least two for each coupling, so as to allow adequate connection and correct mutual positioning of the two elements.
These operations, owing to the number of profiled elements used and therefore to the large number of connections to be provided, require long execution times and a large number of fixing screws; furthermore, in view of the stresses, mainly shear stresses, to which the screws are subjected, said screws may break, consequently entailing a technical drawback.
It is also noted that at least two operators are required in order to correctly perform the connections, so that a first operator keeps the elements to be connected in the correct position and the second one actually produces the various connections; accordingly, the assembly and installation costs of the panel increase.
The aim of the present invention is to provide a device for connection between a first structural element and a second structural element of a cabinet for an electrical panel which allows to simplify the connection of said elements, facilitating assembly and therefore reducing its time requirements.
Within the scope of this aim, an object of the present invention is to provide a device for connection between a first structural element and a second structural element of a cabinet for an electrical panel which allows an optimum distribution of the stresses to which the connection is subjected, so as to avoid any mechanical failures.
Another object of the present invention is to provide a device for connection between a first structural element and a second structural element of a cabinet for an electrical panel which allows to optimize the use of labor required to provide said panel, with a consequent cost benefit.
Another object of the present invention is to provide a device for connection between a first structural element and a second structural element of a cabinet for an electrical panel which allows to reduce the number of fixing screws used with respect to the known art, accordingly reducing the number of the corresponding fixing operations.
Another object of the present invention is to provide a device for connection between a first structural element and a second structural element of a cabinet for an electrical panel which is highly reliable, relatively easy to manufacture and at competitive costs.
This aim, these objects and others which will become apparent hereinafter are achieved by a device for connection between a first structural element and a second structural element of a cabinet for an electrical panel, characterized in that it comprises a substantially flat body for resting against an abutment surface formed by said first element, at least one pair of protruding wings being formed on said flat body and being suitable to enter corresponding slots formed in the first element and to geometrically mate in seats formed in the second element.
The connection device according to the invention allows simplification of the operations for mutually connecting the two structural elements, allowing to provide faster assembly operations, optimize the use of labor and improve the distribution of the stresses involved.
Further characteristics and advantages of the invention will become apparent from the description of preferred but not exclusive embodiments of the connection device frame according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: